Individuals who suffer from certain medical conditions are often required to keep an auto-injector or prefilled syringe nearby in order to address a medical need. A few examples of this are insulin pens for people with diabetes, EPIPENS for those with food and insect stings allergies, and antidotes for soldiers at risk of exposure to chemical and/or biological toxins in the field. For example, an allergic reaction may occur in a location physically distant from the nearest hospital or medical facility. For example, bee stings, are more likely to occur outside than indoors. Food containing peanuts are more likely to be supplied to the individual away from a controlled home environment like at a baseball park. Having a portable epinephrine auto-injector nearby enables emergency intervention after an exposure to an allergen.
Size is an issue when it comes to auto-injectors. Many owners of the devices do not carry it with them and a compact device may make it more likely that they will. Common epinephrine auto injector case sizes are about 6 inches by 1½ inches by 1 inch, making them difficult to carry without a secondary carrying device like a purse and/or backpack and/or other container.